Before start to do VCO layout

[ninge]

vco layout

Hi ALL,

I have Started 3 stage differential Ring cell VCO layout, Before to start to layout what are main things, i need to worry about. Please anyone guide me to do the same...

Thanks in Advance,
Ninge

 

[sunking]

you can refer to
the art of analog layout

and add guarding ring, match, and so on

 

[koti]

Hi Ninge,

1) Devices formation & fabbrication process.

2) Design rule document and GDS layer usage.

3) Basic knowledge on design capture & verification tools (cadences, laker. mentor, etc)

4) Follow the guidelines (matching, current ratings, critical nets, routing, etc)

5) Specifications (datasheet)

6) Verification runs (drc, lvs, dfm, pex)

Thanks & Regards
Koti

 

[AdvaRes]

I think that Floorplanning and Routing is the most prior things to think of a lot.

 

[varma_cs012]

From my experience while doing VCO layout you need to concentrate on the delay blocks connections matching. That is the only one we need to take care. All others anyway we will generally it self take care for every block. I mean guardring and matching transistors and etc...!! Please correct me if I am wrong any where. Thank You.

 

[jecyhale]

It is up to your frequecny of VCO.
if the frequency is larger GHz, the most important is paracitor CAP of the wire.
Sometime it will very impact you design.
but if the frequency is very low, the matching will be more important.

 

[gksivas]

Hi jecyhale
thanks for this information.
u told that reduce parasitic cap for the VCO, if it is working at high speed. more than GHz means? how many GHzs.
another doubt is ,we have to reduce CAP (PARASITIC) for wire or total VCO.
Ps clarify

 

[gksivas]

In VCO layout we have to take care for phase signals also. phase zero (P0) signal has connection to digital part. we have to take care about net lengths and parasitics for phase signals.